1. Field of the Invention
This invention relates to a damping device for toilet seat or toilet lid in a western-style toilet, and a toilet equipped with the damping device.
2. Description of the Related Art
In some high-quality western-style toilets, in order to prevent an impact sound from occurring when the toilet seat or lid is dropped, damping devices (or slow-closing devices) have been provided on the axis of rotation of the toilet seat or toilet lid in order to mitigate the force of rotational motion. For example, in the toilet seat and toilet lid opening/closing device disclosed in Japanese Unexamined (Kokai) Patent Application No. Hei 4[1992]-259424, as shown in FIG. 26, hinges 202 and 203 for the toilet seat 201 and hinges 205 and 206 for the toilet lid 204 are placed side-by-side, and opening and closing devices 207 and 208 that have damping functions are provided outside these hinges.
With this opening and closing device, a driving force transfer hole 210 such as a square hole is formed in one of the hinges 202 of the toilet seat 201, and a driving force non-transfer hole (not shown in the figure) that does not transfer drive force is formed in the other hinge 203. In addition, a driving force non-transfer hole (not shown in the figure) is formed in one of the hinges 205 for the toilet seat cover 204, and a drive force transfer hole 212 is formed in the other hinge 206. Thus, one of the hinge pins 215 links the hinge 202 of the toilet seat 201 and one of the opening-closing devices 207, and the other hinge pin 216 links the hinge 206 of the toilet lid 204 and the other opening/closing device 208. As a result, the rotation of the toilet seat 201 in the downward direction is damped by one of the opening/closing devices 207, and rotation of the toilet lid 204 in the downward direction is damped by the other opening-closing device 208.
Another opening/closing device for toilet seats or toilet lids is disclosed in Japanese Kokai Patent Application No. Hei 8[1996]-117148, shown in FIG. 27. An attachment member 222 is fastened to the toilet 221, and opening/closing devices 223, 224 having symmetrical orientations are inserted into the attachment member 222. Hinges 225 that constitute the attachment parts for the toilet seat are then disposed on both sides of the attachment member 222, and hinges 226 that constitute the attachment parts for the toilet lid are disposed on both sides of hinges 225. An attachment pin 227 is attached on the side of the opening/closing device 223, and an attachment pin 228 is attached on the side of the opening/closing device 224, while passing through the hinges 225 and 226.
On the other hand, with common western-style toilets, a variety of integrated toilet seat and lid units having different shapes or colors are available, and may be interchangeably installed on toilets. In the United States in particular, these types of toilet seat/toilet lid units are sold at low cost, and users may obtain toilet seat/toilet lid units that match their personal preferences. It is common for users themselves to dispose of old units, and use screws to attach the newly purchased unit. This attachment is carried out by providing an attachment member having a retention part that retains the rotating shaft and fastening flange between the hinge part of the toilet lid and hinge part of the toilet seat, so that attachment may be carried out by fastening this attachment member to the toilet. With toilets on which this type of toilet seat/toilet lid unit is installed, there is no damping mechanism on the side of the toilet to which it is attached, and a loud impact noise is produced when the toilet seat or toilet lid is released when closing the toilet seat, etc. Moreover, damage due to the impact of dropping ensues whereby the hinge parts are broken or the toilet seat or toilet lid is broken.
The opening/closing devices 207, 208 in the opening/closing device for toilet seats and toilet lids disclosed in Japanese Unexamined (Kokai) Patent Application No. Hei 4[1992]-259424 (FIG. 26) have a format whereby they are attached to the side surface of the toilet. This format generally involves attachment to the base cover of a warm water bidet-type toilet seat disposed on both sides of the toilet. For this reason, it is difficult to attach the opening/closing devices 207, 208 with toilets that do not have warm water bidet-type toilet seats. Moreover, the hinge 202 of the toilet seat 201 and the hinge 205 of the toilet lid 204 are in close contact, and the hinge 203 of the toilet seat 201 and the hinge 206 of the toilet lid 204 are in close contact, so there is the danger that the toilet lid 204 will also tend to move downward due to frictional forces when the toilet seat 201 is moved downward.
Moreover, the opening/closing devices 207, 208 are disposed with mirror symmetry, so they are not identical in terms of their damping directions. Specifically, the directions of action of the damping functions must be opposite, so the devices must be structurally different. For this reason, the cost of the opening/closing devices 207 and 208 increases. Moreover, it is necessary not to mistake the left and right parts when attaching them, and assembly errors may easily occur.
Moreover, with the opening/closing device for toilet seats and toilet lids of the toilet disclosed in Japanese Kokai Patent Application No. Hei 8[1996]-117148 (FIG. 27), the opening/closing devices 223, 224 must have a large attachment member 222, so the space for sitting on the toilet 221 is decreased. Moreover, the hinges 225 and 226 are in contact on one side, and the hinges 225 and 226 are also in contact on the other side, so that the same problem occurs as in Japanese Kokai Patent Application No. Hei 4[1992]-259424 described above. Moreover, the opening/closing devices 223, 224 are disposed with mirror symmetry, so the damping direction is not the same for the left and right sides, as with the opening/closing devices 207, 208. For this reason, the same problems arise in this regard as in Japanese Kokai Patent Application No. Hei 4[1992]-259424 described above.
Thus, with conventional opening/closing devices, a spring member is provided on the rotating shaft, which strongly applies a damping force in the final range when a toilet seat or toilet lid undergoes rotational falling, but the structure is complicated, large, costly and difficult to assemble. Moreover, fine response to changes in operating torque of the rotating member is problematic, and it is thus difficult to produce a high-quality feel during use. On the other hand, replaceable toilet seat/toilet lid units, while may be readily removed and attached according to personal preference, have no damping function.
Accordingly, the present invention is directed to a damping device for toilet seat and lid unit that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a damping device for a toilet seat/toilet lid unit in a western-style toilet that is easy to install and has a simple structure and low cost.
Another object of the present invention is to provide a damping device for a toilet seat/toilet lid unit in which parts with the same shape and same structure may be attached as-is at the left and right attachment points using two damping devices.
Yet another object of the present invention is to provide a damping device for a toilet seat/toilet lid unit in which control of the rotational force of the seat and/or lid is gradually increased with the rotation of the toilet seat and/or lid.
Additional features and advantages of the invention will be set forth in the description which follows and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the present invention provides a damping device including a casing, a rotor disposed in an interior space of the casing to form an annular chamber between the casing and the rotor, and a damping mechanism including a viscous liquid disposed in the chamber, the viscous liquid exerting frictional forces to damp the relative rotation between the rotor and the casing in a first rotation direction, the damping force increasing when the rotor and the casing rotate relative to each other from a first relative angular position to a second relative angular position in the first rotation direction. The damping mechanism does not damp the relative rotation of the rotor and the casing in the direction opposite the first rotation direction.
In particular, the casing has at least one protrusion protruding inwardly from the interior surface to the interior space. The rotor has a core with a radius that varies angularly such that the core and the protrusion of the casing forms a gap when the rotor and the casing are at the first relative angular position, and the core and the protrusion come into contact when the rotor and casing rotate relatively from the first relative angular position to or near the second relative angular position, whereby the contact generates a damping force that impedes the relative rotation of the rotor and the casing in the first rotation direction. Further, the protrusion of the casing extends in an axial direction and divides the annular chamber into at least two parts. The viscous liquid flows between the parts of the chamber through the gap between the protrusion and the core of the rotor when the rotor and the casing rotate relatively, and the protrusion impedes the flow of the viscous liquid to generate a damping force that impedes the relative rotation of the rotor and the casing. The interior space defined by the casing may have a radius that decreases with an angular position within an angular range.
In addition, the damping device includes at least one movable valve disposed within the annular chamber between the casing and the core of the rotor and controlling the flow of the viscous liquid within the chamber, the valve being latched to a retaining part of a protrusion of the rotor and moves with the rotor, a latching position of the movable valve changing with the direction of rotation of the rotor. The casing further has an end portion substantially perpendicular to a rotation axis of the rotor and the casing, where a depression is provided on an inner surface of end portion, the depression having a cross-sectional area in the radial direction that varies with an angular position defined on the casing.
According to another aspect of the present invention, a toilet seat and toilet lid unit is provided which incorporates the damping device, where the rotation of the toilet seat and/or lid is damped by the damping device. The toilet seat and toilet lid each have two hinges, and one damping device is disposed between one seat hinge and one lid hinge, and another damping device is disposed between the other seat hinge and the other lid hinge. The two damping devices have the same external appearance.
According to yet another aspect of the present invention, a western-style toilet bowl is provided having toilet seat and toilet lid unit which incorporates the damping device.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.